The TBI says 15-year-old Elizabeth Thomas, the teen at the center of an Amber Alert that has drawn nationwide attention, was found safe in Northern California on Thursday morning.

At a news conference Thursday afternoon, TBI spokesman Josh DeVine said the agency received a tip around 11 p.m. Wednesday from someone who had encountered Thomas and her former teacher, 50-year-old Tad Cummins. The caller said they were living in a cabin in a remote area of Cecilville, CA.

The TBI reached out to authorities in Siskiyou County, CA, who said they had received the same tip from the same person.

Authorities responded to the area and located Cummins’ Nissan Rogue. The vehicle’s original license plate had been removed, but officials were able to confirm it belonged to Cummins through its VIN.

The vehicle was placed under surveillance. Around 9:30 a.m. Thursday, Cummins left the cabin and was taken into custody without incident. Thomas was walking behind Cummins and was detained for her own safety, authorities said.

The cabin they were staying in is tucked away next to a river in a remote part of the county. Officials said the cabin had two cots but no power. A resident in the area said the cabin was under construction.

Investigators said Cummins and Thomas were only in the area for about two days before getting caught.

According to the Siskiyou County Sheriff's Office, two loaded handguns were recovered at the cabin, along with personal items belonging to Thomas and Cummins.

The sheriff's office said both were cooperative and thanked the officers for their professionalism. At one point, Cummins allegedly said, "I'm glad this is over."

Officials said Thomas is “healthy and unharmed," but they are concerned about her emotional and mental condition.

TBI Director Mark Gwyn said Thomas will soon be on her way back to Tennessee. Officials with the TBI, FBI and the Maury County Sheriff’s Office flew to the area Thursday to continue their investigation. Thomas will fly back on TBI aircraft sometime Friday.

Thomas was reported missing after being dropped off by a friend at the Shoney's in Columbia, TN, on March 13. An Amber Alert was issued on March 14.

The last confirmed sighting of Cummins and Thomas was in Oklahoma City on March 15.

The TBI added Cummins to its Top 10 Most Wanted list on March 17.

Cummins is being held at the Siskiyou County Jail without bond. He is awaiting extradition to Tennessee, where he will be charged with sexual contact with a minor and aggravated kidnapping.

Acting U.S. Attorney Jack Smith said his office had also filed a federal charge of transportation of a minor across state lines for criminal sexual intercourse. The charge carries a minimum 10-year sentence. Click here to read the full criminal complaint.

Cummins is also charged in Siskiyou County, CA, with kidnapping and possession of stolen property.

According to the criminal complaint, Cummins’ wife found a note on March 13 saying he was traveling to Virginia Beach to clear his head. In the note, he urged his wife not to call police.

During the course of the investigation, detectives also learned from Cummins’ wife that he had refilled his Cialis prescription three days before disappearing.

Investigators said Cummins booked a motel room in Oklahoma on March 16 and 17. That room only had one bed.

The complaint says during their stay, Cummins and Thomas went to Walmart and bought several items, including snacks, women’s razors and lubricant.

Gwyn said the agency received more than 1,500 leads during the search, reaching all 50 states.

“What happened in California this morning, however, proves it only takes one person to lead to a successful end. We are extremely thankful the hard work of all partners in this search has paid off. We’re also grateful for the public’s support and vigilance throughout this search effort," said Gwyn in a news release.

Elizabeth Thomas’ sister, Kat Thomas, reacted to the news that her sister had been found.

“I’ve been telling people all along she is in a commune, because most kidnap victims are held in small counties and no one recognizes them,” she said. “They just hide out like normal people.”

The TBI initially said Elizabeth Thomas had been found in a commune, but later said they were found in a cabin, not a commune. Investigators said the area where Elizabeth Thomas and Cummins were found is very remote with little or no cell service.

Cummins' sister, Daphne Quinn, released this statement about the arrest:

We are so thankful that they have both been found safe. And we are incredibly grateful to the tipster who is responsible for finding them. This is an excellent example of 'when you see something, say something.

Maury County Public Schools issued the following statement on Thursday:

The news of Elizabeth Thomas’ safe return is wonderful news for our community, and now, we can begin healing as a community, school district and as families touched by the AMBER alert. Thanks go to all who have kept the message of finding Elizabeth Thomas and working on her safe return as top-of-mind throughout the nation. The efforts of the Tennessee Bureau of Investigation, Maury County Sheriff’s office, nationwide law enforcement community and media outlets promoting awareness of this case have brought us to this safe conclusion, and Maury County Public Schools wants to thank these many professionals for the good news today. We continue our efforts here with the policy-review task force whose members are focused on developing consistent procedures to assist each school when faced with allegations and investigations. Again, Maury County Public Schools is grateful to everyone who worked tirelessly to bring Elizabeth Thomas home safely. The TBI will be holding a press conference at 3 p.m. CST.

Stay with Channel 4 and WSMV.com for updates on this story.

Cummins told authorities in California when he was arrested "I'm glad this is over."